1. Field of the Invention
The present invention relates to absorbent articles for absorbing body fluids and exudates, such as urine and fecal material. More particularly, the present invention relates to absorbent garments, such as disposable diapers and adult incontinence garments, which include a hydrophilic lotionized bodyside liner for improved skin health benefits.
2. Description of the Related Art
Conventional absorbent articles, such as disposable diapers, employ absorbent materials located between a liquid pervious bodyside liner and a liquid impermeable outer cover to absorb body exudates. Such conventional absorbent articles have typically included elasticized waistbands and leg cuffs to help reduce the leakage of body exudates. Some conventional absorbent articles have also included elasticized containment or barrier flaps at the leg or waist sections of the article to further reduce leaks.
Typically, the liquid pervious bodyside liners have been constructed of nonwoven materials such as spunbond polyolefin materials. Unfortunately, such materials do not always provide a soft, nonabrasive contact with the skin. In particular, during continuous use of absorbent articles containing such liners, the wearer""s skin can become quite irritated and red particularly in the presence of urine and feces. The abrasion resulting from such liners and the presence of urine and feces can undesirably lead to the onset of diaper dermatitis (diaper rash). Diaper dermatitis can afflict almost every infant at some time during the diaper wearing years. Although other factors influence the onset of diaper dermatitis, critical factors include the abrasiveness of the bodyside liner and the hydration level of the wearer""s skin.
To prevent body exudates from contacting the wearer""s skin, the caregiver often applies skin protective products directly to the skin of the wearer before positioning the article on the wearer. Such products have included petrolatum, mineral oil, talc, corn starch, or various other commercially available rash creams or hydrophilic lotions. This procedure typically involves the caregiver applying the products to their hand and then transferring the products to the wearer""s skin.
To eliminate the caregiver from contacting the products and to reduce skin abrasion and improve skin health, hydrophilic lotion formulations can be applied to the bodyside liners such that, in use, the hydrophilic lotion formulation either transfers to the skin or provides lubricity thereby reducing the friction between the liner and the skin. However, conventional lotion formulations have typically been hydrophobic liquids, hydrophobic semi solids, or hydrophobic solids based formulations at room temperature. However, since these lotion formulations are hydrophobic, they have sometimes adversely affected the ability of the absorbent article to accept body exudates and, in particular, urine discharges, from the wearer. As a result, the add-on amount and total surface area covered by such hydrophobic hydrophilic lotions has been limited. Moreover, the hydrophobic nature of these formulations has made it difficult to incorporate hydrophilic, cosmetic and active ingredients into the formulation
Further, such formulations have been unstable and tended to migrate away from the surface of the liner into the liner and absorbent core of the absorbent articles leaving less on the surface to transfer to the skin or provide the reduced abrasion. This migration problem is particularly evident at higher temperatures such as those at the skin surface in use or those in typical storage conditions in warm climates.
Thus, conventional absorbent articles, such as those described above, have not been completely satisfactory. For example, hydrophobic lotions which have been incorporated on the liners of such articles have adversely affected the absorbency of the articles and have migrated such that a less effective amount has been applied to the wearer""s skin or been located between the skin and the liner in use. As a result, the wearer""s skin has remained susceptible to rashes, abrasion and irritation. Accordingly, there remains a need for absorbent articles which provide improved skin health. In particular, there remains a need for absorbent articles which include a hydrophilic lotion on the bodyside liner which does not adversely affect absorbency, which exhibits reduced migration, and in which other ingredients are readily incorporated.
In response to the difficulties and problems discussed above, a new disposable absorbent article which has an improved hydrophilic lotionized bodyside liner has been discovered. In particular, it has been discovered that a superior hydrophilic lotion treated bodyside liner for an absorbent article can be made by (1) applying to the outer bodyfacing surface of the bodyside liner, a melted moisturizing/protective/healing hydrophilic lotion formulation comprising a hydrophilic solvent, a polyethylene glycol having as molecular weight of at least about 720 and a fatty alcohol; and (2) resolidifying the formulation to form a distribution, preferably a uniform distribution, of solid deposits on the bodyfacing surface of the liner. Because the formulation is a solid at room temperature and rapidly solidifies after deposition, it has less tendency to penetrate and migrate into the liner and absorbent body of the article during processing and at elevated storage temperatures. Compared to liners treated with liquid or semi-solid hydrophobic formulations, the hydrophilic lotion formulations of the present invention have a reduced adverse affect on absorbency and leave a greater percentage of the added formulation on the bodyfacing surface of the liner where it can contact and transfer to the wearer""s skin to provide a benefit.
When employed in the present disclosure, the terms xe2x80x9ccomprisesxe2x80x9d, xe2x80x9ccomprisingxe2x80x9d and other derivatives from the root term xe2x80x9ccomprisexe2x80x9d are intended to be open-ended terms that specify the presence of any stated features, elements, integers, steps, or components, but do not preclude the presence or addition of one or more other features, elements, integers, steps, components, or groups thereof.
As used herein, the term xe2x80x9cviscosityxe2x80x9d refers to the viscosity in centipoises determined according to ASTM D3236, entitled xe2x80x9cStandard Test Method for Apparent Viscosity of Hot Melt Adhesives and Coating Materials.xe2x80x9d
As used herein, the phrase xe2x80x9cmelting pointxe2x80x9d refers to the temperature at which the majority of the melting occurs, it being recognized that melting actually occurs over a range of temperatures.
As used herein, the phrase xe2x80x9cmelt point viscosityxe2x80x9d refers to the viscosity of the formulation at the temperature at which the majority of the melting occurs, it being recognized that melting actually occurs over a range of temperatures.
As used herein, the phrase xe2x80x9cpenetration hardnessxe2x80x9d refers to the needle penetration in millimeters according to ASTM D 1321, xe2x80x9cNeedle Penetration of Petroleum High molecular weight polyethylene glycoles.xe2x80x9d Lower needle penetration hardness values correspond to harder materials.
As used herein, the term xe2x80x9cz-direction migration lossxe2x80x9d refers to the value obtained when subjecting an absorbent article having a hydrophilic lotion formulation on the bodyfacing surface thereof to the Z-Direction Lotion Migration Test set forth below.
As used herein, the term xe2x80x9ccd-direction migration lossxe2x80x9d refers to the value obtained when subjecting an absorbent article having a lotion formulation on the bodyfacing surface thereof to the CD-Direction Lotion Migration Test set forth below.
In one aspect, the present invention resides in an absorbent article having a bodyside liner which includes a hydrophilic lotion formulation on the outer bodyfacing surface thereof. The hydrophilic lotion formulation comprises from about 10 to about 90 weight percent of a hydrophilic solvent, from about 5 to about 90 weight percent of a high molecular weight polyethylene glycol, and from about 0 to about 60 weight percent of a fatty alcohol.
In a particular embodiment, the hydrophilic lotion formulation is applied to the bodyside liner at a temperature no more than about 10xc2x0 C. above a melting point of the hydrophilic lotion formulation to reduce migration of the hydrophilic lotion formulation on the bodyside liner.
In another aspect, the invention resides in an absorbent article which includes an outer cover, a liquid permeable bodyside liner which defines a bodyfacing surface and which is connected in superposed relation to the outer cover, and an absorbent body which is located between the bodyside liner and said outer cover. The absorbent article also includes a hydrophilic lotion formulation on at least a portion of the bodyfacing surface of the bodyside liner. The hydrophilic lotion formulation includes a hydrophilic solvent and the article defines a z-direction migration loss of no more than about 55% when subjected to the Z-Directional Lotion Migration Test set forth herein.
In some embodiments, the hydrophilic solvent is selected from the group consisting of propylene glycol, polyethylene glycols with an average molecular weight of less than 720, glycerin, sorbitol solutions, methoxyisopropanol, PPG-2 propyl ether, PPG-2 butyl ether, PPG-3 methyl ether, dipropylene glycol propyl ether, dipropylene glycol butyl ether, dipropylene glycol, methyl propanediol, propylene carbonate, water soluble/dispersible polypropylene glycols, ethoxylated polypropylene glycol, hydrogenated starch hydrolysates, silicone glycols, and the like and mixtures thereof.
Moreover, in some embodiments, the polyethylene glycol is selected from the group consisting of PEG 6000 polyethylene glycol, PEG 8000 polyethylene glycol, PEG 10000 polyethylene glycol and mixtures thereof. Further, in some embodiments, the fatty alcohol is selected from the group consisting of C14 to C30or greater fatty alcohols.
For example, in a particular aspect, the present invention provides an absorbent article which includes an outer cover; a liquid permeable bodyside liner which defines a bodyfacing surface and which is connected in superposed relation to the outer cover, and an absorbent body which is located between the bodyside liner and the outer cover. The absorbent article also includes a hydrophilic lotion formulation on at least a portion of the bodyfacing surface of the bodyside liner which includes from about 30 to about 70 weight percent of a solvent selected from the group consisting of propylene glycol, low molecular weight polyethylene glycol and mixtures thereof, from about 15 to about 25 weight percent polyethylene glycol selected from the group consisting of PEG 6000 polyethylene glycol, PEG 8000 polyethylene glycol, PEG 10000 polyethylene glycol and mixtures thereof, and from about 15 to about 25 weight percent of a fatty alcohol selected from the group consisting of stearyl alcohol, behenyl alcohol and mixtures thereof based on a total weight of the hydrophilic lotion formulation.
The various aspects of the present invention advantageously provide an absorbent article with improved skin health benefits. In particular, the hydrophilic lotionized liner provides a soft, smooth contact with the wearer""s skin and reduced levels of skin irritation. Moreover, because the hydrophilic lotion formulations applied to the liner are more stable and have a higher viscosity than conventional hydrophilic lotion formulations, particularly at higher temperatures, a greater percentage of the added hydrophilic lotion remains on the surface of the liner where it can readily contact and transfer to the wearer""s skin to provide the benefit. Further, if desired, a lower amount of the hydrophilic lotion formulation can be added to the liner to provide the same benefit at a lower cost due to the localization of the hydrophilic lotion at the surface of the liner.
Moreover, since the hydrophilic lotion formulations applied to the liner of the absorbent articles of the present invention are hydrophilic, the absorbent articles have maintained high levels of absorbency and rapid liquid intake. As such, the hydrophilic lotions can be applied in greater amounts and over greater percentages of the overall surface area on the bodyside liner for improved transfer to the skin and resulting skin health. As a result, the skin of the wearers of such absorbent articles should remain less susceptible to rashes, abrasion and irritation.